SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '625c03b74da34cb8e7dfa9c1f23e78cc55319db67921e2fc438b4816e5a44dcd' 
  AND token = '+d+vCWminsgVcDy6Z3JV4UnL6fFNw8mKt6TCGUguF84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}